The shutter speed you use is going to be dependent on how sunny it is, your aperture, and your ISO

So let's pretend that it's a nice, bright sunny day, you're at f/5.6 (assuming you're using a tele, and I'm guessing you're not using a high-end f/2.8 tele), and your ISO is at 400 (the noise isn't very noticeable and will let you be slightly faster)

Since you're talking about shutter speed, I'm guessing you have a DSLR with PSAM modes. The best thing to do would be to set your aperture and ISO to whatever (whatever you like, they're your pictures) and then set your camera to Aperture Priority (as well as being on matrix metering) and just point around the field. Point at the ground, point at the red side of the bunkers, the blue side, point at the fence, and look at what shutter speed the camera wants to use. With the conditions I described it'll probably give you numbers between 1/250" and 1/4000".

Then, set your camera to manual, and take practice shots using different shutter speeds and look at your pictures and see which shutter speed is giving you a proper exposure while still giving you clear photos (use manual, not AP. You don't want your camera using 1/2000" for one picture, and then 1/500" for the next one. You can always edit your photos later, which is worlds easier to do if your photos are consistent).

There is no one magical shutter speed, play around! Do you want super still photos? Do you want just enough blur in there to see the trail of a ball? Do whatever looks best to you.